System.Windows.Forms.CheckedListBox.OnItemClick C# (CSharp) Method

		internal override void OnItemClick (int index)
		{			
			if ((CheckOnClick || last_clicked_index == index) && index > -1) {
				if (GetItemChecked (index))
					SetItemCheckState (index, CheckState.Unchecked);
				else
					SetItemCheckState (index, CheckState.Checked);
			}
			
			last_clicked_index = index;
			base.OnItemClick (index);
		}